There are many diseases that can include or begin with wheezing.
Or, wheezing could be caused by the environment - as in too much ammonia in the coop (from droppings), or mold in wet bedding.
Some diseases that can cause wheezing are not caused by bacteria, so they cannot be treated with antibiotics.
I would not simply start dosing with antibiotics without having any idea what she had.
I would quarantine her and keep an eye on her to see if and how the symptoms progress. I would also keep an eye on my other birds to see if any others develop similar symptoms.
If you really want to know what you are dealing with, in order to know how best to treat or manage any disease that is in your flock (and this could include culling), you could get your bird tested for disease. Don't know where you live but your state might have an agricultural testing lab that offers this and I think many diseases can be tested for using a tracheal swab. This might be the next step if this birds continues to worsen and the rest of your flock comes down with the same thing.